Job Description

Lead Experimentation Engineer (Front End)

Location: Chancery Lane (EC4Y 0HA), hybrid working 3 days in the office, 2 days working from home/another location
Function: Martech & Engineering
Salary: £50,000 - £55,000 dependant on skills and experiences + up to 20% bonus + health + up to 10% matched pension + bens

We’re looking for a Lead Experimentation Engineer to help shape how customers experience our website. Experimentation is central to how we optimise performance, and this role sits at the heart of turning insight and ideas into live, impactful tests.
You’ll take agreed test plans and bring them to life by building A/B experiments that reach real customers and deliver measurable improvements to both experience and commercial results.
Why join us?
• Your work goes live fast and directly influences customer behaviour
• Strong leadership buy in, experimentation is recognised as a key driver of growth
• A hands-on role combining coding, customer thinking, and commercial impact
• Exposure to a wide range of teams including Trading, Pricing, CRO, Analytics and IT
What you’ll do
• Own the build and deployment of website experiments using HTML, CSS and JavaScript
• Translate test plans and designs into robust, production ready A/B tests
• Leverage experimentation platforms to deliver high-impact front-end experiences at scale
• Act as the technical authority for experimentation across the team
• Apply a customer first mindset while improving conversion and performance
• Ensure thorough QA across browsers and devices to ensure high-quality delivery
• Set engineering standards and review experimentation code to ensure quality and scalability
• Collaborate closely with technical and nontechnical stakeholders
• Guide and mentor engineers working on experimentation
What you’ll bring
• Proven front-end engineering experience (HTML, CSS, JavaScript)
• Experience building experiments in an experimentation platform such as Adobe Target or similar.
• Strong QA discipline and attention to detail
• Confidence communicating with stakeholders - this role is not “code only”
• Curiosity, problem-solving and a desire to see your work make a real impact
• A strong commercial mindset, with a clear understanding of how experimentation drives revenue, conversion and customer value.
Nice to haves
• Experience implementing marketing tagging with Adobe Launch, Google Tag Manager or similar
• Experience with analytics like Adobe Analytics, Google Analytics or similar
• Experience with UX design
You’ll join a forward-thinking team that embraces innovation, experimentation, and continuous improvement. Your work will have a direct and visible impact on business results, in a role where technical skill and analytical thinking truly shine.
We’re proud to be a Top Employer for 14 consecutive years, a top apprenticeship employer, #10 in the Stonewall Workplace Equality Index, and a Top 25 Exemplary Employer in the Investing in Ethnicity Parliamentary Matrix.
Interested?
If you enjoy building experiments that improve real customer journeys and want your work to visibly influence business performance - apply now.